peri-Naphthotriazines and related compounds. Part III. Some photochemical reactions: synthesis of 1-methylacenaphtho[5,6-bc]pyridine

Abstract

The photolysis, in a variety of solvents, of 1-methylnaphtho[1,8-de]triazine gives products which suggest the intermediacy of a biradical, formed from the triazine by loss of nitrogen, in which the two radical centres react independently. Examples of addition to olefins, hydrogen abstraction, and aromatic substitution have been found. In particular, reaction with vinyl bromide gives 1-methyl-1-azaphenalene, apparently by a two-step cycloaddition followed by elimination of hydrogen bromide. The new aromatic heterocycle, 1-methylacenaphtho[5,6-bc]-pyridine, has been obtained by a similar reaction.